Then it dawned on me as to whether there's any Xenforo specific php code that could be added to bench.php or micro_bench.php to simulate testing how Xenforo PHP related code would respond to different PHP version benchmarks. Guess it would be equivalent to running testing against Xenforo actual install just without the MySQL overhead involved to just test Xenforo specific PHP code/routines.

So along the lines of running modified bench.php and micro_bench.php with added Xenforo PHP specific execution patterns etc.